The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Eveline A Crone - One of the best experts on this subject based on the ideXlab platform.
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the influence of sex steroids on structural Brain Maturation in adolescence
PLOS ONE, 2014Co-Authors: Cedric P M P Koolschijn, Jiska S Peper, Eveline A CroneAbstract:Puberty reflects a period of hormonal changes, physical Maturation and structural Brain reorganization. However, little attention has been paid to what extent sex steroids and pituitary hormones are associated with the refinement of Brain Maturation across adolescent development. Here we used high-resolution structural MRI scans from 215 typically developing individuals between ages 8-25, to examine the association between cortical thickness, surface area and (sub)cortical Brain volumes with luteinizing hormone, testosterone and estradiol, and pubertal stage based on self-reports. Our results indicate sex-specific differences in testosterone related influences on gray matter volumes of the anterior cingulate cortex after controlling for age effects. No significant associations between subcortical structures and sex hormones were found. Pubertal stage was not a stronger predictor than chronological age for Brain anatomical differences. Our findings indicate that sex steroids are associated with cerebral gray matter morphology in a sex specific manner. These hormonal and morphological differences may explain in part differences in Brain development between boys and girls.
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sex differences and structural Brain Maturation from childhood to early adulthood
Developmental Cognitive Neuroscience, 2013Co-Authors: Cedric P M P Koolschijn, Eveline A CroneAbstract:Recent advances in structural Brain imaging have demonstrated that Brain development continues through childhood and adolescence. In the present cross-sectional study, structural MRI data from 442 typically developing individuals (range 8–30) were analyzed to examine and replicate the relationship between age, sex, Brain volumes, cortical thickness and surface area. Our findings show differential patterns for subcortical and cortical areas. Analysis of subcortical volumes showed that putamen volume decreased with age and thalamus volume increased with age. Independent of age, males demonstrated larger amygdala and thalamus volumes compared to females. Cerebral white matter increased linearly with age, at a faster pace for females than males. Gray matter showed nonlinear decreases with age. Sex-by-age interactions were primarily found in lobar surface area measurements, with males demonstrating a larger cortical surface up to age 15, while cortical surface in females remained relatively stable with increasing age. The current findings replicate some, but not all prior reports on structural Brain development, which calls for more studies with large samples, replications, and specific tests for Brain structural changes. In addition, the results point toward an important role for sex differences in Brain development, specifically during the heterogeneous developmental phase of puberty.
Vasily L Yarnykh - One of the best experts on this subject based on the ideXlab platform.
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direct comparison between apparent diffusion coefficient and macromolecular proton fraction as quantitative biomarkers of the human fetal Brain Maturation
Journal of Magnetic Resonance Imaging, 2019Co-Authors: Alexandra M Korostyshevskaya, Irina Yu Prihodko, A A Savelov, Vasily L YarnykhAbstract:BACKGROUND Apparent diffusion coefficient (ADC) is known as a quantitative biomarker of prenatal Brain Maturation. Fast macromolecular proton fraction (MPF) mapping is an emerging method for quantitative assessment of myelination that was recently adapted to fetal MRI. PURPOSE To compare the capability of ADC and MPF to quantify the normal fetal Brain development. STUDY TYPE Prospective. POPULATION Forty-two human fetuses in utero (gestational age [GA] = 27.7 ± 6.0, range 20-38 weeks). FIELD STRENGTH/SEQUENCE 1.5 T; diffusion-weighted single-shot echo-planar spin-echo with five b-values for ADC mapping; spoiled multishot echo-planar gradient-echo with T1 , proton density, and magnetization transfer contrast weightings for single-point MPF mapping. ASSESSMENT Two operators measured ADC and MPF in the medulla, pons, cerebellum, thalamus, and frontal, occipital, and temporal cerebral white matter (WM). STATISTICAL TESTS Mixed repeated-measures analysis of variance (ANOVA) with the factors of pregnancy trimester and Brain structure; Pearson correlation coefficient (r); Hotelling-Williams test to compare strengths of correlations. RESULTS From the 2nd to 3rd trimester, ADC significantly decreased in the thalamus and cerebellum (P < 0.005). MPF significantly increased in the medulla, pons, thalamus, and cerebellum (P < 0.005). Cerebral WM had significantly higher ADC and lower MPF compared with the medulla and pons in both trimesters. MPF (r range 0.83, 0.89, P < 0.001) and ADC (r range -0.43, -0.75, P ≤ 0.004) significantly correlated with GA and each other (r range -0.32, -0.60, P ≤ 0.04) in the medulla, pons, thalamus, and cerebellum. No significant correlations or distinctions between regions and trimesters were observed for cerebral WM (P range 0.1-0.75). Correlations with GA were significantly stronger for MPF compared with ADC in the medulla, pons, and cerebellum (Hotelling-Williams test, P < 0.003) and similar in the thalamus. Structure-averaged MPF and ADC values strongly correlated (r = 0.95, P < 0.001). DATA CONCLUSION MPF and ADC demonstrated qualitatively similar but quantitatively different spatiotemporal patterns. MPF appeared more sensitive to changes in the Brain structures with prenatal onset of myelination. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;50:52-61.
Tomas Paus - One of the best experts on this subject based on the ideXlab platform.
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mapping Brain Maturation and cognitive development during adolescence
Trends in Cognitive Sciences, 2005Co-Authors: Tomas PausAbstract:Non-invasive mapping of Brain structure and function with magnetic resonance imaging (MRI) has opened up unprecedented opportunities for studying the neural substrates underlying cognitive development. There is an emerging consensus of a continuous increase throughout adolescence in the volume of white matter, both global and local. There is less agreement on the meaning of asynchronous age-related decreases in the volume of grey matter in different cortical regions; these might equally represent loss (‘pruning’) or gain (intra-cortical myelination) of tissue. Functional MRI studies have so far focused mostly on executive functions, such as working memory and behavioural inhibition, with very few addressing questions regarding the Maturation of social cognition. Future directions for research in this area are discussed in the context of processing biological motion and matching perceptions and actions.
Arthur W. Toga - One of the best experts on this subject based on the ideXlab platform.
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mapping Brain Maturation
FOCUS, 2006Co-Authors: Arthur W. Toga, Paul M. Thompson, Elizabeth R. SowellAbstract:Human Brain Maturation is a complex, lifelong process that can now be examined in detail using neuroimaging techniques. Ongoing projects scan subjects longitudinally with structural magnetic resonance imaging (MRI), enabling the time-course and anatomical sequence of development to be reconstructed. Here, we review recent progress on imaging studies of development. We focus on cortical and subcortical changes observed in healthy children, and contrast them with abnormal developmental changes in early-onset schizophrenia, fetal alcohol syndrome, attention-deficit–hyperactivity disorder (ADHD) and Williams syndrome. We relate these structural changes to the cellular processes that underlie them, and to cognitive and behavioral changes occurring throughout childhood and adolescence.
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mapping continued Brain growth and gray matter density reduction in dorsal frontal cortex inverse relationships during postadolescent Brain Maturation
The Journal of Neuroscience, 2001Co-Authors: Elizabeth R. Sowell, Kevin D Tessner, Paul M. Thompson, Arthur W. TogaAbstract:Recent in vivo structural imaging studies have shown spatial and temporal patterns of Brain Maturation between childhood, adolescence, and young adulthood that are generally consistent with postmortem studies of cellular Maturational events such as increased myelination and synaptic pruning. In this study, we conducted detailed spatial and temporal analyses of growth and gray matter density at the cortical surface of the Brain in a group of 35 normally developing children, adolescents, and young adults. To accomplish this, we used high-resolution magnetic resonance imaging and novel computational image analysis techniques. For the first time, in this report we have mapped the continued postadolescent Brain growth that occurs primarily in the dorsal aspects of the frontal lobe bilaterally and in the posterior temporo-occipital junction bilaterally. Notably, maps of the spatial distribution of postadolescent cortical gray matter density reduction are highly consistent with maps of the spatial distribution of postadolescent Brain growth, showing an inverse relationship between cortical gray matter density reduction and Brain growth primarily in the superior frontal regions that control executive cognitive functioning. Inverse relationships are not as robust in the posterior temporo-occipital junction where gray matter density reduction is much less prominent despite late Brain growth in these regions between adolescence and adulthood. Overall Brain growth is not significant between childhood and adolescence, but close spatial relationships between gray matter density reduction and Brain growth are observed in the dorsal parietal and frontal cortex. These results suggest that progressive cellular Maturational events, such as increased myelination, may play as prominent a role during the postadolescent years as regressive events, such as synaptic pruning, in determining the ultimate density of mature frontal lobe cortical gray matter.
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in vivo evidence for post adolescent Brain Maturation in frontal and striatal regions
Nature Neuroscience, 1999Co-Authors: Elizabeth R. Sowell, Paul M. Thompson, Colin J Holmes, Terry L Jernigan, Arthur W. TogaAbstract:We spatially and temporally mapped Brain Maturation between adolescence and young adulthood using a whole-Brain, voxel-by-voxel statistical analysis of high-resolution structural magnetic resonance images (MRI). The pattern of Brain Maturation during these years was distinct from earlier development, and was localized to large regions of dorsal, medial and orbital frontal cortex and lenticular nuclei, with relatively little change in any other location. This spatial and temporal pattern agrees with convergent findings from post-mortem studies of Brain development and the continued development over this age range of cognitive functions attributed to frontal structures.
Joseph A Helpern - One of the best experts on this subject based on the ideXlab platform.
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does diffusion kurtosis imaging lead to better neural tissue characterization a rodent Brain Maturation study
NeuroImage, 2009Co-Authors: Matthew M Cheung, Kevin C Chan, Joseph A Helpern, Liqun Qi, E X WuAbstract:article i nfo Diffusion kurtosis imaging (DKI) can be used to estimate excess kurtosis, which is a dimensionless measure for the deviation of water diffusion profile from Gaussian distribution. Several recent studies have applied DKI to probe the restricted water diffusion in biological tissues. The directional analysis has also been developed to obtain the directionally specific kurtosis. However, these studies could not directly evaluate the sensitivity of DKI in detecting subtle neural tissue alterations. Brain Maturation is known to involve various biological events that can affect water diffusion properties, thus providing a sensitive platform to evaluate the efficacy of DKI. In this study, in vivo DKI experiments were performed in normal Sprague-Dawley rats of 3 different ages: postnatal days 13, 31 and 120 (N=6 for each group). Regional analysis was then performed for 4 white matter (WM) and 3 gray matter (GM) structures. Diffusivity and kurtosis estimates derived from DKI were shown to be highly sensitive to the developmental changes in these chosen structures. Conventional diffusion tensor imaging (DTI) parameters were also computed using monoexponential model, yielding reduced sensitivity and directional specificity in monitoring the Brain Maturation changes. These results demonstrated that, by measuring directionally specific diffusivity and kurtosis, DKI offers a more comprehensive and sensitive detection of tissue microstructural changes. Such imaging advance can provide a better MR diffusion characterization of neural tissues, both WM and GM, in normal, developmental and pathological states.
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does diffusion kurtosis imaging lead to better neural tissue characterization a rodent Brain Maturation study
NeuroImage, 2009Co-Authors: Matthew M Cheung, Kevin C Chan, Edward S Hui, Joseph A HelpernAbstract:Diffusion kurtosis imaging (DKI) can be used to estimate excess kurtosis, which is a dimensionless measure for the deviation of water diffusion profile from Gaussian distribution. Several recent studies have applied DKI to probe the restricted water diffusion in biological tissues. The directional analysis has also been developed to obtain the directionally specific kurtosis. However, these studies could not directly evaluate the sensitivity of DKI in detecting subtle neural tissue alterations. Brain Maturation is known to involve various biological events that can affect water diffusion properties, thus providing a sensitive platform to evaluate the efficacy of DKI. In this study, in vivo DKI experiments were performed in normal Sprague-Dawley rats of 3 different ages: postnatal days 13, 31 and 120 (N=6 for each group). Regional analysis was then performed for 4 white matter (WM) and 3 gray matter (GM) structures. Diffusivity and kurtosis estimates derived from DKI were shown to be highly sensitive to the developmental changes in these chosen structures. Conventional diffusion tensor imaging (DTI) parameters were also computed using monoexponential model, yielding reduced sensitivity and directional specificity in monitoring the Brain Maturation changes. These results demonstrated that, by measuring directionally specific diffusivity and kurtosis, DKI offers a more comprehensive and sensitive detection of tissue microstructural changes. Such imaging advance can provide a better MR diffusion characterization of neural tissues, both WM and GM, in normal, developmental and pathological states.